Method's eight rules in La Logique ou L'Art de Penser

1. Leave no term even slightly obscure or equivocal without defining it.
2. In definitions use only terms that are perfectly known or have already been explained.

Two rules for axioms

3. In axioms require everything to be perfectly evident.
4. Accept as evident what need only a little attention to be recognized as true.

Two rules for demonstrations

5. Prove all propositions that are even slightly obscure, using in their proofs only definitions that
have preceded, axioms that have been granted, or propositions that have already been
demonstrated.
6. Never exploit the equivocation in terms by failing to substitute mentally the definitions that
restrict and explain them.

Two rules for method

7. Treat things as much as possible in their natural order, beginning with the most general and the
simplest, and explaining everything belonging to the nature of the genus before proceeding to
particular species.
8. Divide each genus as much as possible into all its species, each whole into all its parts, and each
difficulty into all its cases.